We are using WP User Frontend Pro with some custom taxonomies (product_cat from WooCommerce). We have a situation where we are starting with product data that about half of the products have product category taxonomy assignments, and half do not have any.
We setup a form to edit the post (‘product') information, and the custom taxonomies are being displayed using the checkbox type in the WPUF Pro form setup.
In testing, we've found that when we go in and try to clear out all custom taxonomy selections, so none of them are checked, it will say successfully saved, but will still leave one checked. If we only have one checked, we can check a different product category, uncheck the first one, and save successfully. It only seems to be the case where we are trying to remove ALL categories where it doesn't successfully save. Any ideas on what might be causing that or a way to prevent it?